Stereoscopic picture.



W. HESS. STBREOSGOPIG PICTURE. APPLIUATION FILED JUNE 1, 1912.

Patented Eeb.16,'1915.

WALTE-R-HESS, OF RAPPERSWIL, SWITZERLAND.

STEBEOSCOPIC PICTURE.

Specification of Letters Patent.

Patented Feb. 16, 1915.

Application led .Tune 1, 1912. Serial No. 700,949.

To altro/1.0m t may concern.'

Be it known that I, WALTER HEss, a citizen of the Republic of Switzerland, resid'- ing at Rapperswil, Switzerland, have invented certain new and useful Improvements in Stercoscopic Pictures; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings and to letters or figures of reference mar-hed thereon, which form a part of this specification.

In order to see images spatially, hitherto two single images located side byV side and belonging to a stereoscopic pair of images have been caused to opticallyvcover each other by means of prisms held before the eyes, or two single stereoscopic images prmted in complementary colors on each other were viewed through transparent, complementary colored plates, `held before the eyes. Inboth cases an optical expedient to be held before the eyes is necessary. For the same purpose the so called aralla'x stereogram has been proposed, which comprises a double image, composed of ne lines of two single stereoscopic images, wherein the lines of the two single images alternate, and a screen having fine opaque lines which are separated by linear spaces. The opaque lines of the screen cover for each eye all those lines of the image which ldo not belong to the single stereoscopic image corresponding with that eye. These stereograms can only be used as transparencies, because when looking on the image through the screen with the naked eye the lines of the screen refract light and are mingled with the lines of the image so as to render the latter unclear, moreover, the image located a slight distance below the screen, is shadowed and darkened.

According to the present invention two ordinary stereoscopic negatives are used in making the picture, and there is provided a series of optical light-collecting elements, arranged side by side, which so refract the light that beams, which come from different directions are collected or focused at different places on the sensitizedl picture surface. Referring to the drawings, in which like parts are similarly designated-Figure l is a plan view on a very much enlarged scale .printing light Figs. 3 and 4 are diagrammatic views -in section, illustrating how a print or picture is made from a negative. Fig. 5 is a diagram illustrating the course of a ray in the operation of printing, and its effect on the print. Fig. 6 isa vertical se'ction showing how the prints are made.

As shown inthe drawings, a smalh transparent plate lc, or lens surface ocelluloid, is provided on its surface a with a large number of small lens elements, here shown as ribs o located side by side. Each rib represents a part of the surface of a cylinder (l. Parallel beams of light f, which enter the plate from the front, are collected and focussed, as a consequence of the cylindrical surface of a single element c. The place g, or focal point toward which the'collection is performed, changes with a change of directioniof the entering beams f. If a print is made from one of a pair of stereoscopic negatives z' placed on top of such a surface composed of such lens elements c, the light passes through the negative z' and the plate lc onto a sensitive layer it, (Fig. 3), so that the does not strike the negative from all directions, but from a definite direction only, no light entering from other directions, and a positive print is produced, which doesnot correspond with the continuous photographic negative, but consists of image portions 1, 3, 5, having intermediate linear spaces. as shown at I, (Fig. 4). The spaces are caused by the absence of printing rays from those directions from which no light was permitted to enter. These linear spaces I use for receiving linear images 2, 4, 6, of a second print II, viz. of the other stereoscopic negative belonging to the same lI f the negative with the image for the right eye is inserted in the printing frame, the right window, l, is opened, in order to perright eye is the left side',

mit `the printing light to enter. Incon'sequence ofthe reversibility of the` courses of the'rays, .this image is only7V to beseenv from that side onl which the opening'or lsource of light is situated, that is, from the right side. When viewing the image, the

located on this side. In an analogous manner a print is made from the other stereoscopic negative for the left eye, and in this instance the left window is opened, `in order to have the light enter from so that the image on the print can be seen only from the left side, that is to say, by the left eye, when looking on the image in the ordinary manner. places, where no light enters, correspond with the blackened inside walls of the box, which keep the light off from all directions, with the exception of the direction in which the window or blind is situated. The box, therefore, acts as a shutter, which for each of the two stereoscopic images keeps the light off from those directions from which the corresponding image must not be seen. The photographic double-positive III (Fig.

4) is thus completed. .When viewed through v the same or through congruent elements.

(Fig. 1) each part of the two prints pr@- duced bythe single negatives can only be seenfrom a distinct direction. Correspondin with the linear spaces of each print (I, III, the rays passing outward to the eyes distinct directions. Each have spaces 1n nuage is` made visible by the optical elements or lens surfaces,.as a consequence of their refractiveaction and visible only in certain directions. Since the prints I, II, used, are two single` stereoscopic photographs, both positives of which are on the same surface III, but visible only from different directions, any one looking at the image through the plate la when holding the image in the'proper position, sees by the oneeye only. the image I, and by the other eye, only the Iimage II, so that the images are caused to be viewed spatially.

The printing of both negatives-mecd not be performed one after the other, but it may also -be do'ne simultaneously, for instance, by the simultaneous projection of the two single images on the same surface from two projector apparatus arranged side by side.

'Since when printing the sin le yimages the rays of light mus/t be kept o from distinct directions, itis advisable not only toy prevent the rays from entering the lens elements from other than said directions, but is also necessary to insure that the rays after enteringv said elements will not be deflected by reflection toward the linearinterspaces, which must be kept free from the other image. This maybe done by a light filter. For example, the plate lf." itself, by coloring its substance, for instance yellow, may act Aturning throu The dark v i w, Fi .-5 designatesfan enteringI ray of e i light e refiected light`y', to y", cannot act directly on Vthe film it, but only by reand being di used by the surface and reected to the sensitive layer. The course which these objectionable reiiected light rays have to pass .within the' plate k or ilter, is therefore much longer than the single course of the direct ray; light ray is therefore much more damped, that is, its intensity is greatly diminished by the filter. It is posslble to render any of the remaining objectionable light rays, for instance, reflected light rays, inactive by a suitable choice of sensitive layer and hard treatment thereof to produce strong contrasts.

The -opticall elements arranged side by side, the sensitive layer and also the light filter, if any be used, may be .joined in one piece or be wholly or partly separated as well during the production of the immediately acting stereoscopic image, as during the observation of the same.

Instead of a-direct photographic print, any equivalent, asa copy produced by impression, may be laid under the optical element.

Thus, the novel product of my novel proc-` ess or method consists of a picture subdivlded by alternating, portions of stereoscopic images III, Fig. 4, viewed through a subdivided lens surface lc corresponding to the subdivisions of the picture, and preferably connected to or combined with such surface la s that no stereoscope, stereoscopic spectacles or separate light filters are,

necessary. Each lens element c of the plate lc will therefore be common to two adjacent subdivisions of the picture, one subdivision pertaining to ing adjacent cylindrical lens elements, each `lens element beingl common to an element.

ofv each stereoscopic picture.

3. A directly viewable stereoscopic picture composed 'of subdivided images of a pair of stereoscopic pictures whose sections alternatmand are adjacent one another, and a celluloid covering having a surface of the reiectedI one stereoscopic view and the other subdivision` to the other stereoscopicA small lens elements, common to adjacent pictures.

4. A directly viewable a pair of stereoscopic of said pictures alternati the other, and a Celluloid each lens element bein sections of the pair o stereoscopic picture composed of strip-like subdivisions of pictures strips of one ng with strips of covering having a surface composed of cylindrical lens elements, each element being common to similar strlps of the pair of pictures.

5. A directly viewable ture composed of subdiv pair of stereoscopic pictu stereoscopic picided images of a res Whose sections ARNOLD LEHNER, HARRY A. MGBRIDE.

a pair of adjacent image 20' 

